positioning 4" fan hole in brick wall

i need to drill a 4" hole in my brick wall for the fart fan in my prospective powder room.

i have made some sort of a sub-ceiling to the powder room, since the bathroom is right above and i wanted to have more space for drain pipes than what the space between the beams offers, i.e. to have more options where to position the toilet etc. this also gives me the option to position the hole in the sub-ceiling space, which is about a foot (the house is really old and the original ceiling is very high, so this reduction is no big deal) or to actually put it between the beams, which would make it harder to reach for drilling.

the basic dilemma is which position will make the least of a negative structural impact in terms of weakening the wall. i am thinking if i position it within a foot below the beam anchors in the brick wall, the weight can be impacting the hole negatively and perhaps introduce cracks around. between the beams might be better but it is harder to reach.

another thing i was thinking of is to put a 4" galvanized steel pipe, if there is such a think, in the hole to reinforce it and then the aluminum sleeve of the hooded vent would go inside it.

positioning 4" fan hole in brick wall

Ama,
I just did one on the last job for an exhaust fan. I used a 1/4" masonry bit and after drawing out a 4 1/4" circle, I used a hammer drill and drilled a series of holes that just about touched each other. Then I took a 1" cold chisel and knocked out the plug in pieces. It didn't come out in one piece. Took about ten minutes. It also helps is you can locate your hole so parts of it hit on mortar joints, which are easier to drill.
Mike Hawkins

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positioning 4" fan hole in brick wall

positioning 4" fan hole in brick wall

It has been years since I thought about it but I remember installing a vent for brick walls somebody made. It just replaced the brick and you adapted the round vent duct work to the back. Looked nice from the outside. Blended right in.